Sick of dumbbell and barbell reps? Kettlebells have been trending for a few years, and, while at least one study from The California State University has shown that traditional weights are more effective for improving upper body and overall strength, kettlebells are still highly efficient instruments for burning fat and increasing muscle strength, according to Men’s Health. That’s because kettlebells activate a ton of different muscles during each rep, increasing metabolism and helping build power endurance. Ask your trainer about incorporating kettlebells, or check for small-group classes like Kettlebell Concept at Club Fit in Briarcliff Manor (914-762-3444; www.clubfit.com/briarcliff).